An anesthesia system, comprising an anesthesia apparatus and an anesthetic dispenser, in which fresh breathing gas is fed to the anesthetic dispenser via a pneumatic interface, is known from EP 0 338 518 B1. The breathing gas is enriched with anesthetic in the anesthetic dispenser at concentrations that can be set at different values. The breathing gas enriched with anesthetic returns to the anesthesia apparatus via the pneumatic interface and is fed to the patient's breathing circuit. There is no electric connection between the anesthesia apparatus and the anesthetic dispenser because of the requirements imposed in terms of safety, reliability and hygiene. The anesthetic dispenser is provided with a code for the type of anesthetic used, which code can be identified by a scanning device provided on the anesthesia apparatus in order to make information on the type of the anesthetic used available to the anesthesia apparatus. Information on the quantity of anesthetic still present is not communicated to the anesthesia apparatus. However, this information is decisive for warning the user of an insufficient quantity of anesthetic in time before or during a medical procedure. The anesthetic is checked in the line in which breathing gas enriched with anesthetic is fed to the patient. The fact that the anesthetic concentration is too low or is not present is thus determined with a time delay relative to the quantity of anesthetic actually present in an anesthetic reservoir of the anesthetic dispenser.
Information on the particular anesthetic dispensing parameters, for example, the concentration or the still available quantity in the anesthetic dispenser, is thus not available to the anesthesia apparatus or it is available only partially.